On-line commerce is now an important part of our economy, mainly because of the efficiency and the ready convenience that on-line commerce provides. As a general principle, ready convenience and good human factors go hand-in-hand. Moreover, each improvement in human factors opens the use of electronic commerce to a larger segment of the population.
Today, however, many would-be participants in electronic commerce (e-commerce) are limited by the capabilities of the computer systems they use to gain access to e-commerce web servers. This limitation is often experienced, for example, by customers who shop on-line. Because the items to be purchased are not actually seen by the customer at the time the items are selected—rather, the items are carried virtually in an abstract shopping cart—the customer is not able to keep track of purchases conveniently.
One way that the lack of visibility may confound a shopper involves the purchase of linked items. Items are linked when the purchase of a primary item, for example a computer printer, is normally coupled with the purchase of a secondary item, for example a power cord for the printer. When the shopper changes the quantity of a primary item in the shopping cart, for example revising the quantity of the order from four printers to six printers, the shopper must remember also to revise the quantity of the secondary item, here from four power cords to six.
If the shopper forgets to change an attribute of the secondary items in the shopping cart in response to each change in a related attribute of the primary items, the shopper's order will not be filled as intended. As a result, the shopper will be disappointed by the on-line shopping experience, and perhaps be disappointed in the on-line merchant as well.
Thus there is a need for a way of helping an on-line shopper maintain the proper relationship in the shopping cart between primary items and secondary items that are normally ordered along with the primary items, so that the on-line merchant may fill the shopper's order as the shopper intends, and so that the shopper maintains confidence in the on-line shopping process.